Reviewed April 2014
What is the official name of the DYSF gene?
The official name of this gene is “dysferlin.”
DYSF is the gene's official symbol. The DYSF gene is also known by other names, listed below.
Read more about gene names and symbols on the About page.
What is the normal function of the DYSF gene?
The DYSF gene provides instructions for making a protein called dysferlin. This protein is found in the thin membrane called the sarcolemma that surrounds muscle fibers. Dysferlin is thought to aid in repairing the sarcolemma when it becomes damaged or torn due to muscle strain. Researchers suggest that dysferlin may also be involved in the formation of new muscle fibers (regeneration) and in inflammation, but little is known about these functions.
How are changes in the DYSF gene related to health conditions?
limb-girdle muscular dystrophy - caused by mutations in the DYSF gene
More than 140 mutations in the DYSF gene that can cause limb-girdle muscular dystrophy type 2B have been identified. Limb-girdle muscular dystrophy is a group of related disorders characterized by muscle weakness and wasting (atrophy), particularly in the shoulders, hips, thighs, and upper arms. Muscle problems caused by DYSF gene mutations, such as limb-girdle muscular dystrophy type 2B and others (see below), are called dysferlinopathies.
DYSF gene mutations may disrupt the function of the dysferlin protein and interfere with the muscle repair process. Studies suggest that inefficient repair of damaged muscle fibers may lead to inflammation and degeneration of muscles, resulting in muscle weakness.
Miyoshi myopathy - caused by mutations in the DYSF gene
More than 100 mutations in the DYSF gene have been found to cause Miyoshi myopathy. This condition is a muscle disorder that is characterized by progressive weakness and atrophy of muscles that are away from the center of the body (distal muscles), particularly those in the legs. The DYSF gene mutations identified in people with Miyoshi myopathy change single amino acids in the dysferlin protein, which impairs the protein's function or results in the production of a nonfunctional protein. A common cause of the condition in people of Japanese ancestry is a mutation that replaces the amino acid tryptophan with the amino acid cysteine at position 999 in dysferlin (written Trp999Cys or W999C).
A lack of normal dysferlin leads to a reduced ability to repair damage done to the sarcolemma of muscle fibers. As a result, damage accumulates and leads to atrophy of the muscle fiber. It is unclear why the DYSF gene mutations that cause Miyoshi myopathy lead to the specific pattern of weakness and atrophy that is characteristic of this disorder.
Some researchers consider Miyoshi myopathy to be a variant of limb-girdle muscular dystrophy (see above) rather than a separate disorder because they are caused by mutations in the same gene and have overlapping signs and symptoms.
- other disorders - caused by mutations in the DYSF gene
DYSF gene mutations also cause another dysferlinopathy called distal myopathy with anterior tibial onset. In this condition, the muscle weakness is most apparent in the muscles of the lower legs. This condition first becomes apparent in a muscle called tibialis anterior, which is located at the front of the lower leg and helps to flex the foot. Distal myopathy with anterior tibial onset later affects the muscles of the upper leg, and affected individuals eventually require wheelchair assistance.
Where is the DYSF gene located?
Cytogenetic Location: 2p13.3
Molecular Location on chromosome 2: base pairs 71,453,119 to 71,686,763
The DYSF gene is located on the short (p) arm of chromosome 2 at position 13.3.
More precisely, the DYSF gene is located from base pair 71,453,119 to base pair 71,686,763 on chromosome 2.
See How do geneticists indicate the location of a gene? in the Handbook.
Where can I find additional information about DYSF?
You and your healthcare professional may find the following resources about DYSF helpful.
You may also be interested in these resources, which are designed for genetics professionals and researchers.
What other names do people use for the DYSF gene or gene products?
- dysferlin, limb girdle muscular dystrophy 2B (autosomal recessive)
- dystrophy-associated fer-1-like 1
- fer-1-like protein 1
Where can I find general information about genes?
The Handbook provides basic information about genetics in clear language.
These links provide additional genetics resources that may be useful.
What glossary definitions help with understanding DYSF?
The resources on this site should not be used as a substitute for
professional medical care or advice. Users seeking information about
a personal genetic disease, syndrome, or condition should consult with a qualified
See How can I find a genetics professional in my area? in the Handbook.